An attachment for a trocar

ABSTRACT

An attachment (1) for a trocar cannula (3) having an access valve (12) located in a proximal end (5) thereof comprises a housing (20) defining an instrument passageway (29). An operating member (43) having an instrument bore (46) is slideable in the instrument passageway (29) from a disengaged state disengaged from the access valve (12) to an engagement state extending through the access valve (12) with the access valve (12) in the open state and shielded from an instrument passing therethrough. A pair of detecting probes (55) carried on a carrier (50) and extending into the instrument bore (46) are urgeable distally from a first state to a second state by a distal end of an instrument being urged distally in the instrument bore (46) for in turn urging the operating member (43) from the disengaged state to the engagement state. A proximal seal (40) in the instrument passageway (29) is urged from a non-sealing state to a sealing state by the operating member (43) being urged from the disengaged state to the engagement state.

The present invention relates to an attachment for a trocar or a trocar cannula, and in particular, to an attachment for a trocar or a trocar cannula for operating an access valve of the trocar or the trocar cannula into an open state. The invention also relates to a trocar or a trocar cannula comprising the attachment.

Throughout this specification, the term “trocar cannula” is used to mean a cannula portion of the trocar having an instrument bore extending therethrough for accommodating instruments into a cavity or vessel of a subject into which the trocar cannula has been inserted prior to a laparoscopic investigative or surgical procedure, or other minimal invasive investigative and surgical procedures. Such a trocar cannula comprises an access valve adjacent the proximal end thereof, which is urgeable from a closed state to an open state by an instrument being inserted therethrough. The term “trocar” is used to mean an assembly of a trocar cannula and a proximal trocar housing secured releasably or otherwise to the proximal end of the trocar cannula. The term “proximal trocar housing” is used to mean a housing which is secured to the proximal end of a trocar cannula, and comprises an instrument bore for accommodating instruments therethrough to the instrument bore of the trocar cannula, and may also include a valving system in the instrument bore for minimising loss of insufflating gases. One or more ports may also be provided in the proximal trocar housing for supplying insufflating gas, as well as liquids and the like through the trocar to the cavity or vessel of a subject.

Trocars are used in laparoscopic surgery and other minimal invasive investigative and surgical procedures both on humans and animals. In the carrying out of such procedures in, for example, the abdominal cavity, one or more trocars are extended through the abdominal wall into the abdominal cavity in order to accommodate surgical instruments and other instruments into the abdominal cavity. In order to provide an operating field for a surgeon in the abdominal cavity, the abdominal cavity is insufflated by a suitable insufflator, which pumps air or an inert gas, for example, carbon dioxide into the abdominal cavity through the trocar or other suitable instrument for insufflating the abdominal or other cavity.

Such trocars comprise a trocar cannula and a proximal trocar housing for accommodating surgical instruments into the trocar cannula and for attaching conduits thereto for supplying insufflating gas and other gases or liquids, which are delivered into the cavity, in which the procedure is being carried out, through the trocar. The trocar cannula is of tubular construction having an elongated instrument bore extending therethrough in order to accommodate instruments as well as a laparoscope and/or an endoscope into the abdominal cavity. It is important that the instrument bore extending through a trocar or the trocar cannula incorporates a sealing system for minimising the escape of insufflating gas from the abdominal cavity. Trocar cannulae, in general, are provided with an access seal adjacent the proximal end of the trocar cannula. Such access seals for sealing an instrument bore extending through a trocar cannula, in general, comprise an annular seal or a valve, for example, a duckbill valve, a dome valve, a cross-slit valve or other such valves located in the instrument bore adjacent the proximal end of the trocar cannula. Such access valves, in general, comprise a resilient material, and in the absence of an instrument in the instrument bore, are resiliently urged into a closed state by virtue of their own inherent resilience. On being engaged by an instrument, such access valves yield into an open state, and sealably bear on the instrument while the instrument is in the instrument bore extending through the access valve, thereby forming a partial seal around parts of the instrument. This in turn reduces the passage of insufflating gas between the seal and the instrument. However, various problems arise with such access valves.

Firstly, the ability of such access valves to form an adequate seal between the instrument, laparoscope or endoscope being inserted through the instrument bore of the trocar cannula is sometimes inadequate, thus allowing uncontrolled escape of insufflating gas from the abdominal cavity.

Secondly, such access valves in a trocar cannula bear on the instrument in the instrument bore, and as an instrument is being withdrawn from the abdominal cavity, body fluids, tissue and other surgical matter on the instruments may be deposited onto the access valve. This results in a serious problem. Where a laparoscope or endoscope is to be entered into the abdominal cavity through the trocar cannula, after a previously withdrawn instrument has deposited body fluids, tissue or other surgical matter on the access valve, as the laparoscope or endoscope is being inserted through the trocar cannula, the deposited matter on the access valve transfers to the lens of the laparoscope or endoscope, which is located adjacent the distal leading end of the laparoscope or endoscope, thus occluding the lens thereof. This prevents image capture by an imaging device through the lens.

Additionally, the leakage and escape of insufflating gas from the abdominal cavity or any other cavity of a subject being insufflated through a trocar causes two problems. Firstly, the loss of the insufflating gas, which in the case of an inert gas such as carbon dioxide, is wasteful. Secondly, and of considerably more importance, such escaping insufflating gas has been found to carry organisms, such as pathogens, viruses and infections from the cavity of a subject being insufflated. These organisms are dispersed directly into an operating theatre from the trocar, and can thus result in healthcare professionals who are carrying out and participating in a procedure, being infected themselves. This is a particularly serious problem in cases where a subject is infected with a virus for which there is no known cure.

There is therefore a need to address at least one of these problems.

The present invention is directed towards providing an attachment for a trocar or a trocar cannula, which addresses at least one of these problems. The invention is also directed towards a trocar or a trocar cannula comprising the attachment.

According to the invention there is provided an attachment for a trocar or a trocar cannula, the trocar or the trocar cannula being of the type comprising an access valve adjacent a proximal end thereof, the attachment comprising a housing defining an instrument passageway extending through the housing from a proximal end to a distal end for accommodating an instrument therethrough, the instrument passageway defining a longitudinally extending main central axis, the housing being engageable with the trocar or the trocar cannula with the instrument passageway aligned with an instrument bore of the trocar or the trocar cannula, and an operating means for operating the access valve in the trocar or the trocar cannula from a closed state to an open state.

In one embodiment of the invention the attachment is engageable with a proximal end of the trocar or the trocar cannula.

In another embodiment of the invention the operating means is configured to engage the access valve of the trocar or the trocar cannula, and preferably, the operating means is configured to extend into the access valve of the trocar or the trocar cannula, and advantageously, the operating means is configured to extend through the access valve of the trocar or the trocar cannula, and preferably, to shield the instrument from the access valve of the trocar or the trocar cannula.

In another embodiment of the invention the operating means is aligned with the instrument passageway.

In one embodiment of the invention the operating means defines an instrument bore extending therethrough for accommodating an instrument therethrough.

Preferably, the instrument bore of the operating means defines a central axis coinciding with the main central axis defined by the instrument passageway.

In one embodiment of the invention the operating means comprises at least one elongated operating member.

In another embodiment of the invention the operating means comprises a pair of spaced apart operating members, and advantageously, the operating members are spaced apart around the main central axis. Preferably, the operating members are equi-spaced apart around the main central axis.

In another embodiment of the invention the at least one elongated operating member comprises a tubular member defining the instrument bore extending therethrough, and preferably, the tubular operating member defines the central axis, and preferably, the central axis defined by the tubular member coincides with the main central axis defined by the instrument passageway.

In one embodiment of the invention the operating means comprises a passive operating means.

In another embodiment of the invention the operating means comprises a static operating means, which preferably, projects from the housing.

In one embodiment of the invention the operating means is configured to engage the access valve of the trocar or the trocar cannula as the attachment is being engaged with the trocar or the trocar cannula.

In another embodiment of the invention the operating means extends distally from the housing.

In an alternative embodiment of the invention the operating means comprises an active operating means, and preferably, the operating means is moveably mounted, and advantageously, the operating means is moveable from a disengaged state disengaged from the access valve of the trocar or the trocar cannula to an engagement state engageable with the access valve of the trocar or the trocar cannula.

In one embodiment of the invention the operating means is slideable from the disengaged state to the engagement state, and preferably, the operating means is slideably mounted in the housing, and preferably, is slideable in the housing from the disengaged state to the engagement state.

In another embodiment of the invention the operating means is located in the instrument passageway, and preferably, is slideable therein from the disengaged state to the engagement state.

In another embodiment of the invention a detecting means is provided and is configured to detect an instrument entering or passing distally through the instrument passageway.

In one embodiment of the invention the operating means is urgeable from the disengaged state to the engagement state in response to the detecting means detecting insertion of the instrument entering or passing distally through the instrument passageway.

In another embodiment of the invention the detecting means is urgeable from a first state to a second state in response to the instrument entering or passing distally through the instrument passageway. Preferably, the detecting means is urgeable distally from the first state to the second state.

In one embodiment of the invention the operating means is urgeable from the disengaged state to the engagement state in response to the detecting means being urged from the first state to the second state.

In one embodiment of the invention the detecting means extends into the instrument passageway, and preferably, the detecting means extends into the instrument passageway in an extended state in the first state thereof.

In one embodiment of the invention the detecting means terminates in a distal, instrument engaging end adapted to engage an instrument being entered into or passing distally through the instrument passageway when the detecting means is in the extended state.

Preferably, the distal, instrument engaging end of the detecting means is adapted to engage a distal end of an instrument being entered into or passing through the instrument passageway when the detecting means is in the extended state.

In another embodiment of the invention the detecting means is urgeable from the first state to the second state by an instrument passing distally through the instrument passageway.

In one embodiment of the invention the detecting means is urgeable in the second state thereof from the extended state extending into the instrument passageway to a third state.

Preferably, the detecting means is urgeable radially relative to the main central axis from the extended state to the third state.

In another embodiment of the invention the detecting means is urgeable from the extended state to the third state in response to an instrument in the instrument passageway, and preferably, the detecting means is adapted to be urgeable by an instrument in the instrument passageway from the extended state to the third state.

In one embodiment of the invention the detecting means in the third state is adapted to engage an instrument in the instrument passageway, and advantageously, the detecting means is adapted to be retained in the third state by an instrument in the instrument passageway engaging the detecting means.

In one embodiment of the invention the detecting means in the second state thereof is moveable from the third state to the extended state in response to a distal end of an instrument being withdrawn from the instrument passageway in a proximal direction past the detecting means.

In another embodiment of the invention the detecting means in the second state thereof is moveable from the third state to the extended state in response to a distal end of an instrument being withdrawn through the instrument passageway in a proximal direction past the detecting means.

Preferably, the detecting means is urgeable longitudinally along the instrument passageway from the first state to the second state.

In another embodiment of the invention a first guide means is provided for guiding the detecting means from the first state to the second state. Preferably, the detecting means extends into the instrument passageway through the first guide means. Advantageously, the first guide means comprises a first guide slot extending into the housing from the instrument passageway and longitudinally along the instrument passageway.

In another embodiment of the invention a second guide means is provided for guiding the detecting means from the extended state to the third state.

In one embodiment of the invention the detecting means is mounted on a carrier.

In another embodiment of the invention the carrier is located externally of the instrument passageway. Preferably, the second guide means is mounted on the carrier.

In one embodiment of the invention the detecting means is slideably mounted on the carrier, and is slidable from the extended state to the third state.

Preferably, the operating means is coupled to the carrier. Advantageously, the operating means is rigidly coupled to the carrier.

In one embodiment of the invention the detecting means extends through a probe accommodating opening extending through the operating means communicating with the instrument bore defined by the operating means. Preferably, the detecting means in the extended state thereof is adapted to extend into the instrument bore defined by the operating means. Advantageously, the detecting means in the extended state thereof is adapted to engage an instrument in the instrument bore defined by the operating means.

In one embodiment of the invention an urging means is provided for urging the operating means from the engagement state to the disengaged state. Preferably, the urging means is responsive to the detecting means being in the extended state for urging the operating means from the engagement state to the disengaged state.

In another embodiment of the invention the urging means is responsive to the distal end of an instrument passing the detecting means proximally for urging the operating means from the engagement state to the disengaged state.

In another embodiment of the invention the urging means is adapted to urge the detecting means from the second state to the first state.

Preferably, the urging means is responsive to the distal end of an instrument passing the detecting means proximally for urging the detecting means from the second state to the first state.

In one embodiment of the invention the urging means is adapted to urge the detecting means from the third state to the extended state.

In another embodiment of the invention the urging means is responsive to the distal end of an instrument passing the detecting means proximally for urging the detecting means from the third state to the extended state.

In another embodiment of the invention the urging means is cooperable with a first camming means for urging the detecting means from the third state to the extended state.

In another embodiment of the invention the urging means is configured to urge the detecting means from the second state to the first state thereof when the detecting means is in the extended state.

In one embodiment of the invention a retaining means is provided for releasably retaining the detecting means in the second state while the detecting means is in the third state.

In another embodiment of the invention the retaining means is located adjacent the distal end of the first guide means.

Preferably, the retaining means comprises a pair of interengageable complementary formations, one of the interengageable complementary formations being formed in or on the housing and the other one of the interengageable complementary formations being formed in or on the detecting means. Advantageously, the one of the interengageable complementary formations formed in the housing is formed adjacent the instrument passageway.

In another embodiment of the invention the retaining means comprises the first camming means.

Preferably, the detecting means is located proximal of the distal end of the instrument passageway. Advantageously, the detecting means is located spaced apart proximally from the distal end of the instrument passageway.

In one embodiment of the invention the detecting means comprises a detecting probe. Preferably, the detecting probe terminates in the distal, instrument engaging end. Advantageously, a pair of detecting means is provided, and preferably, each detecting means comprises a detecting probe.

In another embodiment of the invention the detecting means comprises an elongated detecting member.

In one embodiment of the invention the detecting means is engageable with the operating means for urging the operating means from the disengaged state to the engagement state, as the detecting means is being urged from the first state to the second state.

In another embodiment of the invention the detecting means is engageable with the operating means for urging the operating means from the engagement state to the disengaged state, as the detecting means is urged from the second state to the first state.

Preferably, the urging means is configured for urging the operating means from the engagement state to the disengaged state through the detecting means, by urging the detecting means from the second state to the first state.

Preferably, the detecting means is urgeable from the third state to the extended state in response to the distal end of the instrument passing proximally in the instrument passageway past the detecting means.

In another embodiment of the invention a sealing means is located in the instrument passageway for sealably engaging an instrument in the instrument passageway for minimising the passage of gases passing proximally through the instrument passageway. Preferably, the sealing means is located adjacent a proximal end of the instrument passageway. Advantageously, the sealing means is spaced apart proximally from the detecting means.

In one embodiment of the invention the sealing means comprises a flexible sealing means. Preferably, the sealing means comprises a deformable flexible sealing means. Advantageously, the sealing means comprises a resilient sealing means.

In one embodiment of the invention the sealing means comprises an annular seal. Preferably, the sealing means extends circumferentially around the instrument passageway.

In one embodiment of the invention the sealing means is mounted in a seal accommodating recess formed in the housing. Preferably, the seal accommodating recess extends into the housing from the instrument passageway. Advantageously, the seal accommodating recess extends circumferentially around the instrument passageway.

Preferably, the seal accommodating recess comprises an annular seal accommodating recess.

In one embodiment of the invention the sealing means is transitionable from a non-sealing state disengaged from an instrument in the instrument passageway to a sealing state sealably engaging an instrument in the instrument passageway. Preferably, the sealing means is adapted to transition in a general radial direction from the non-sealing state to the sealing state. Advantageously, the sealing means is adapted to transition from the non-sealing state to the sealing state under its own inherent resilience. Ideally, the sealing means is adapted to transition from the sealing state to the non-sealing state under its own inherent resilience.

In one embodiment of the invention the sealing means is transitionable from the non-sealing state to the sealing state in response to the detecting means detecting insertion of an instrument into the instrument passageway or an instrument being urged distally in the instrument passageway.

In another embodiment of the invention the sealing means is operable from the non-sealing state to the sealing state in response to the detecting means being urged from the first state to the second state.

Preferably, the sealing means is operable from the non-sealing state to the sealing state in response to movement of the operating means from the disengaged state to the engagement state. Advantageously, the operating means is adapted in the disengaged state thereof to retain the sealing means in the non-sealing state.

In one embodiment of the invention the operating means is adapted in the disengaged state thereof to engage the sealing means in the non-sealing state. Advantageously, the operating means is adapted in the disengaged state thereof to shield an instrument in the instrument passageway from the sealing means.

In one embodiment of the invention the sealing means is adapted to transition from the non-sealing state to the sealing state in response to disengagement thereof by the operating means.

In another embodiment of the invention the operating means is adapted to disengage the sealing means as the operating means is being urged from the disengaged state to the engagement state.

In one embodiment of the invention the sealing means is mounted on the operating means and is moveable with the operating means.

In another embodiment of the invention the sealing means is urgeable from the non-sealing state to the sealing state in response to movement of the operating means from the disengaged state to the engagement state.

In one embodiment of the invention a second camming means is provided adjacent the seal accommodating recess cooperable with the sealing means for urging the sealing means from the non-sealing state to the sealing state in response to movement of the operating means from the disengaged state to the engagement state. Preferably, the second camming means is located distally in the seal accommodating recess. Advantageously, the second camming means comprises a camming surface extending around the seal accommodating recess. Preferably, the camming surface is of frusto-conical shape. Advantageously, the camming surface converges distally.

In another embodiment of the invention at least one collecting port is located in the instrument passageway for applying a vacuum adjacent the instrument passageway for drawing gases passing proximally through the instrument passageway therefrom.

In another embodiment of the invention the at least one collecting port is located adjacent the proximal end of the instrument passageway.

Preferably, the at least one collecting port is located proximal of the sealing means. Advantageously, the at least one collecting port is located spaced apart proximally from the sealing means.

In another embodiment of the invention a connecting port is provided for connecting the at least one collecting port to a vacuum system.

In another embodiment of the invention a plurality of the collecting ports are provided spaced apart circumferentially around the instrument passageway.

In another embodiment of the invention a gallery is located in the housing with which the at least one collecting port communicates. Preferably, the connecting port extends from the gallery.

In another embodiment of the invention the housing comprises an elongated substantially tubular housing defining the instrument passageway.

In another embodiment of the invention the operating means comprises a tubular operating member defining the instrument bore extending therethrough.

The invention also provides a trocar comprising a trocar cannula and the attachment according to the invention mounted on one of the trocar and the trocar cannula.

In one embodiment of the invention the attachment is mounted adjacent the proximal end of the one of the trocar and the trocar cannula.

In another embodiment of the invention the one of the trocar and the trocar cannula on which the attachment is mounted comprises an access valve located adjacent the proximal end thereof, the access valve being engageable by the operating means of the attachment for operating the access valve from a closed state to an open state.

In another embodiment of the invention the access valve is operable from the closed state to the open state in response to engagement thereof by the operating means of the attachment.

In another embodiment of the invention the access valve is engageable by the operating means of the attachment when the operating means is in the engagement state.

In another embodiment of the invention the access valve comprises a flexible membrane urgeable into the closed state under inherent resilience of the access valve.

In one embodiment of the invention the access valve is operable from the closed state to an open state by deforming the membrane thereof.

In another embodiment of the invention the attachment is secured to the one of the trocar and the trocar cannula by engaging the housing of the attachment with the one of the trocar and the trocar cannula.

In another embodiment of the invention the attachment is releasably secured to the one of the trocar and the trocar cannula.

The advantages of the invention are many. A particularly important advantage of the attachment according to the invention when attached to a trocar or a trocar cannula which comprises an access valve, is that there is no danger of an instrument, being urged distally through the attachment into the trocar or trocar cannula, coming into contact with the access valve. Thereby the risk of any biological matter or other matter, which may have been previously deposited on the access valve, being transferred onto the distal end of an instrument as the instrument is being urged distally through the attachment into the trocar or cannula is avoided. This is a particularly important advantage, when the instrument is a laparoscope or an endoscope whereby any contamination of the lens, which is located adjacent the distal end of the laparoscope or endoscope, with such biological or other matter would result in occlusion or partial occlusion of the lens, which would thereby prevent image capture by an imaging device through the lens of the laparoscope or endoscope.

The attachment enables the access valve of the trocar or trocar cannula to be operated from the closed state to the open state prior to the distal end of an instrument reaching the access valve as the instrument is being urged distally through the attachment. Additionally, the access valve of the trocar or trocar cannula is retained in the open state by the presence of an instrument in the attachment, until the distal end of the instrument has passed the access valve, as the instrument is being withdrawn proximally through the attachment. Thereby, the risk of biological or other matter from the cavity, which may be attached to the instrument, being deposited on the access valve from the instrument, as the instrument is being withdrawn, is also avoided.

These advantages are further enhanced when the attachment is configured to shield an instrument from the access valve while the access valve is being retained in the open state.

A further advantage of the invention is achieved in embodiments of the invention in which a proximal seal is located adjacent the proximal end of the instrument passageway of the attachment, and the proximal seal is operated from the non-sealing state to the sealing state sealing an instrument in the instrument passageway, as the operating means is operated from the disengaged state to the engagement state for operating the access valve into the open state, in that as the access valve is being opened, the proximal seal seals the instrument in the instrument passageway, thereby minimising and substantially eliminating leakage of gases proximally through the attachment while the access valve is in the open state.

A further advantage of the invention is achieved when the operating means is adapted to operate the proximal seal from the sealing state to the non-sealing state prior to the distal end of an instrument, being withdrawn proximally through the attachment, reaching the proximal seal, which in turn minimises any risk of biological or other matter which may be attached to the instrument being deposited onto the proximal seal. This advantage is enhanced when the operating means is adapted to shield an instrument from the proximal seal while the proximal seal is in the non-sealing state.

The invention will be more clearly understood from the following description of some preferred embodiments thereof, which are given solely by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional partly perspective side elevational view of an attachment according to the invention illustrated mounted on a trocar cannula, which with the attachment of FIG. 1 mounted thereon is also according to the invention,

FIG. 2 is a view similar to FIG. 1 of the attachment of FIG. 1 mounted on the trocar cannula, but with a part of the attachment in a different state to that of FIG. 1 ,

FIG. 3 is a cross-sectional partly perspective side elevational view of the attachment of FIG. 1 mounted on a trocar cannula in use,

FIG. 4 is a view similar to FIG. 3 with the attachment of FIG. 1 mounted on the trocar cannula in use but illustrated in a different state to that of FIG. 3 ,

FIG. 5 is a cross-sectional side elevational view of a portion of the attachment of FIG. 1 ,

FIG. 6 is a cross-sectional side elevational view similar to that of FIG. 5 of the portion of FIG. 5 of the attachment of FIG. 1 in a different state to that of FIG. 5 ,

FIG. 7 is an exploded perspective view of the attachment of FIG. 1 and the trocar cannula of FIG. 1 ,

FIG. 8 is a cross-sectional partly perspective side elevational view of a detail of the attachment of FIG. 1 ,

FIG. 9 is a view similar to FIG. 8 of the detail of FIG. 8 in a different state to that of FIG. 8 ,

FIG. 10 is a cross-sectional perspective view of a portion of the attachment of FIG. 1 ,

FIG. 11 is a cross-sectional perspective view of another part of the attachment of FIG. 1 ,

FIG. 12 is a cross-sectional perspective view of the part of FIG. 11 ,

FIG. 13 is another perspective view of the part of FIG. 11 ,

FIG. 14 is a perspective view of a detail of the attachment of FIG. 1 ,

FIG. 15 is a view similar to FIG. 14 of the detail of FIG. 14 illustrating a portion of the detail of FIG. 14 in a different state to that of FIG. 1 ,

FIG. 16 is a view similar to FIG. 14 of the detail of FIG. 14 illustrating a part of the detail in a different state to the states of FIGS. 14 and 15 ,

FIG. 17 is a perspective view of another part of the attachment of FIG. 1 ,

FIG. 18 is a cross-sectional partly perspective side elevational view of an attachment according to another embodiment of the invention illustrated mounted on a trocar cannula, which with the attachment of FIG. 18 mounted thereon is also according to the invention,

FIG. 19 is a view similar to that of FIG. 18 of the attachment and the trocar cannula of FIG. 18 illustrating a part of the attachment of FIG. 18 in a different state to that of FIG. 18 , and

FIG. 20 is an enlarged cross-sectional perspective side elevational view of a detail of the attachment of FIG. 18 .

Referring to the drawings, and initially to FIGS. 1 to 17 thereof, there is illustrated an attachment according to the invention indicated generally by the reference numeral 1 for mounting on a trocar or a trocar cannula adjacent a proximal end thereof for operating an access valve in the trocar or the trocar cannula from a closed state to an open state, and also for minimising the escape of insufflating and other gases passing proximally through the trocar or the trocar cannula into the environment from, for example, a vessel or a cavity of a subject being insufflated, and into which the trocar cannula extends. Typically, the vessel or cavity would be insufflated to enable a minimal invasive investigative or surgical procedure to be carried out. In this embodiment of the invention the attachment 1 is mounted on a trocar cannula 3 adjacent the proximal end 5 thereof. Before describing the attachment 1, the trocar cannula 3 will first be described.

The trocar cannula 3 extends from the proximal end 5 to a distal end 6. An instrument bore 8 extends through the trocar cannula 3 from the proximal end 5 to the distal end 6 for accommodating an instrument 10, for example, an endoscope, a laparoscope or other surgical instrument therethrough. A pair of securing members 11 extend proximally from respective locations adjacent the proximal end 5 of the trocar cannula 3 on respective opposite sides of the trocar cannula 3 for releasably engaging and securing the attachment 1 to the trocar cannula 3 adjacent the proximal end 5 thereof, as will be described in more detail below.

An access valve 12 is located in the instrument bore 8 adjacent the proximal end 5 of the trocar cannula 3 for minimising the escape of insufflating and other gases from a subject. The access valve 12 is of the type which is commonly referred to as a duckbill valve and comprises a flexible membrane of resilient material, which under its own inherent resilience is urged naturally from an open state illustrated in FIGS. 2 and 4 into a closed state as illustrated in FIGS. 1 and 3 , and when in the closed state is of duckbill shape. The material of the duckbill valve 12 is of such resilience and flexibility as to yield from the closed state to the open state on engagement with a distal end 14 of the instrument 10 as the instrument 10 is being urged through the duckbill valve 12 and into the instrument bore 8 extending through the trocar cannula 3, and to sealably bear on the instrument when in the open state. However, the access valve in the trocar cannula 3, may be any other type of access valve, for example, a dome valve, a cross-slit valve, or any other such access valve, which is urgeable from a closed state to an open state against its own inherent resilience on engagement with an instrument passing through the access valve.

Typically, the membrane of the duckbill valve 12 is shaped to form a pair of opposite valving portions 15 sealably abutting each other in the closed state of the duckbill valve 12 along respective abutment sealing edges 16. The valving portions 15 are configured to yield into the open state of the duckbill valve 12 under the pressure of the distal end 14 of the instrument 10 as the instrument 10 is being urged against them, thereby resulting in the valving portions 15 parting along the abutment edges 16 to open the duckbill valve 12 for accommodating the instrument 10 therethrough. The abutting edges 16 sealably engage the instrument extending through the duckbill valve 12 partly around its circumferential surface in order to reduce the leakage of insufflating and other gases in a proximal direction from the instrument bore 8 of the trocar cannula 3. An annular rim 17 of the duckbill valve 12 is provided with an inwardly extending annular recess 18 which extends circumferentially around the rim 17. The recess 18 is configured to releasably engage an annular flange 19 extending inwardly from and circumferentially around the trocar cannula 3 into the instrument bore 8 adjacent the proximal end 5 thereof for sealably securing, and typically releasably securing, the duckbill valve 12 in the trocar cannula 3. As discussed above such trocar cannulae as the trocar cannula 3, and such access valves as the duckbill valve 12 and other such access valves will be well known to those skilled in the art, and further description should not be required.

A particular problem of such duckbill valves as the duckbill valve 12 is that by virtue of the fact that as the instrument 10 is being urged into the bore 8 of the trocar cannula 3, the distal end 14 of the instrument 10 must engage the duckbill valve 12. Additionally, as instruments are being withdrawn through the instrument bore 8 of the trocar cannula 3, such instruments, for example, surgical instruments used in cutting, suturing or taking samples from an organ in the cavity being insufflated may carry deposits such as blood, tissue and other surgical and biological matter as the instrument is being withdrawn from the cavity through the instrument bore 8 of the trocar cannula 3. Such deposits may attach to the duckbill valve 12 and remain thereon. Thus, on an instrument, being subsequently urged into the instrument bore 8 of the trocar cannula 3, the deposits on the duckbill valve 12 may transfer from the duckbill valve and may attach to the instrument being urged through the instrument bore 8 into the cavity. This is particularly problematic in the event of the subsequent instrument being a laparoscope where the deposits on the duckbill valve 12 may adhere to the lens adjacent the distal end of the laparoscope, thereby occluding or partly occluding the lens, and preventing image capturing by an image capturing device through the lens, thereby rendering the laparoscope ineffective.

The attachment according to the invention is provided to address this problem, while at the same time minimising the escape of insufflating and other gases from the instrument bore 8 of the trocar cannula 3.

Referring now in particular to FIGS. 1 to 17 the attachment 1 according to the invention will now be described. The attachment 1 comprises a housing 20 which may be of any suitable material, for example, a plastics or other polymer material. The housing 20 comprises an outer peripheral wall 22 which extends distally from a proximal wall 23 to a distal wall 24, and defines with the proximal and distal walls 23 and 24 a substantially sealed hollow interior region 25.

A tubular housing 27 of circular transverse cross-section extends substantially centrally through the hollow interior region 25 of the housing 20 from the proximal wall 23 to the distal wall 24 and defines an elongated instrument passageway 29 also of circular transverse cross-section extending therethrough from a proximal end 30 to a distal end 31 for accommodating the instrument 10, which as discussed above may be an endoscope, a laparoscope, a surgical instrument, or any other such instrument. A proximal opening 32 in the proximal wall 23 and a distal opening 33 in the distal wall 24 communicate with the instrument passageway 29. The proximal and distal openings 32 and 33 are of similar diameter to that of the instrument passageway 29. The instrument passageway 29 as well as the proximal opening 32 and the distal opening 33 together define a longitudinally extending main central axis 35. When the attachment 1 is secured to the proximal end 5 of the trocar cannula 3 the main central axis 35 defined by the instrument passageway 29 coincides with a central axis 36 defined by the instrument bore 8 of the trocar cannula 3.

A sealing means comprising a proximal seal 40 of a flexible resilient material is located in the instrument passageway 29 of the attachment 1 towards the proximal end 30 thereof. The proximal seal 40 is urgeable from a sealing state, illustrated in FIGS. 2 and 4 for sealably and slideably engaging the instrument 10 in the instrument passageway 29, for in turn sealing the instrument passageway 29 with the instrument 10 located therein, to a non-sealing state, illustrated in FIGS. 1 and 3 , clear of the instrument 10. The proximal seal 40 and its operation will be described in more detail below.

An operating means, in this embodiment of the invention, an active operating means for operating the duckbill valve 12 of the trocar cannula 3 from the closed state illustrated in FIGS. 1 and 3 to the open state illustrated in FIGS. 2 and 4 , comprises an elongated tubular operating member 43 of circular transverse cross-section extending between a proximal end 44 and a distal end 45. The operating member 43 is located in the instrument passageway 29. The operating member 43 defines a longitudinally extending instrument bore 46 extending from the proximal end 44 to the distal end 45 thereof for accommodating the instrument 10 therethrough. The instrument bore 46 defines a central longitudinally extending central axis 47 which coincides with the main central axis 35 defined by the instrument passageway 29. The operating member 43 is slideable longitudinally in the instrument passageway 29 from a disengaged state illustrated in FIGS. 1 and 3 to an engagement state illustrated in FIGS. 2 and 4 . The operation of the operating member 43 between the disengaged state and the engagement state is described in detail below.

When the attachment 1 is secured to the trocar cannula 3, and when the operating member 43 is in the disengaged state, the distal end 45 of the operating member 43 is disengaged from the duckbill valve 12, and the duckbill valve is in the closed state. Additionally, when the operating member 43 is in the disengaged state, the proximal end 44 of the operating member 43 extends through the proximal seal 40 for retaining the proximal seal 40 in the non-sealing state for shielding the instrument 10 in the instrument passageway 29 from the proximal seal 40, so that the instrument 10 can pass through the instrument passageway 29 unimpeded by the proximal seal 40.

When the operating member 43 is in the engagement state, the operating member 43 engages and extends through the duckbill valve 12 of the trocar cannula 3 for urging the duckbill valve 12 from the closed state to the open state, and for retaining the duckbill valve 12 in the open state, and also for shielding the instrument 10 from the duckbill valve 12. Therefore, with the operating member 43 in the engagement state, the instrument 10 can be urged passed the duckbill valve 12 unimpeded by and shielded from the duckbill valve 12. Additionally, when the operating member 43 is in the engagement state, the operating member 43 is disengaged from the proximal seal 40, and the proximal seal 40 is in the sealing state sealing the instrument 10 in the instrument passageway 29.

Therefore, in the disengaged state of the operating member 43, an instrument in the instrument passageway 29 is shielded by the operating member 43 from the proximal seal 40, and the access valve, such as the duckbill valve 12, in the trocar cannula 3 is in the closed state, thereby preventing leaking of gases proximally from the trocar cannula 3. In the engagement state of the operating member 43, an instrument in the instrument passageway 29 and in the instrument bore 8 of the trocar cannula 3 is shielded by the operating member 43 from the access valve in the trocar cannula, and the proximal seal is in the sealing state sealing the instrument in the instrument passageway 29 and preventing leaking of gases proximally from the instrument passageway 29.

A carrier, comprising an outer tubular carrier member 50 is located in the hollow interior region 25 and extends circumferentially around the tubular housing 27. The carrier member 50 is rigidly connected to the operating member 43, and is moveable longitudinally with the operating member 43 from a proximal state illustrated in FIGS. 1 and 3 to a distal state illustrated in FIGS. 2 and 4 as the operating member 43 moves from the disengaged state to the engagement state. The carrier member 50 comprises a cylindrical wall 53 and an inwardly extending circular flange 59 extending inwardly from the cylindrical wall 53. Four radial connecting members 48 extending radially inwardly from the circular flange 59 rigidly connect the carrier member 50 to the operating member 43. The radial connecting members 48 extend between the carrier member 50 and the operating member 43 at 90° intervals around the operating member 43.

A first guide means for guiding the carrier member 50 between the proximal and the distal states comprises four elongated guide slots 49 extending longitudinally along and radially through the tubular housing 27. The guide slots 49 are equi-spaced apart circumferentially around the tubular housing 27 at 90° intervals and slideably accommodate the radial connecting members 48 for guiding the carrier member 50 between the proximal and distal states. The carrier member 50 carries two carrier elements 51 which are equi-spaced apart circumferentially around the carrier member 50 at 180° intervals. The carrier elements 51 are mounted on the flange 59 of the carrier member 50 adjacent two of the radial connecting members 48. A proximal limit means comprising an annular shoulder 52 extending outwardly from and circumferentially around the tubular member 27 is engageable by the carrier elements 51 to limit movement of the carrier member 50 in the proximal direction beyond the proximal state, and in turn to limit movement of the operating member 43 in the proximal direction beyond the disengaged state. A distal limit means defined by the distal wall 24 of the housing is engageable with the flange 59 of the carrier member 50 to limit movement of the carrier member 50 in a distal direction beyond the distal state thereof, and in turn to limit movement of the operating member 43 beyond the engagement state.

A detecting means for detecting an instrument, such as the instrument 10 entering or passing distally through the instrument passageway 29 comprises two elongated detecting probes 55 slideably located in the respective carrier elements 51. The detecting probes 55 extend from the carrier elements 51 into the instrument passageway 29, and in turn into the instrument bore 46 of the operating member 43. The detecting probes 55 extend into the instrument passageway 29 through two of the guide slots 49 in the tubular housing 27 which also form corresponding first guide means, namely, guide slots 60 for guiding the detecting probes 55 longitudinally in the instrument passageway 29 as will be described in detail below. Probe accommodating openings 61 in the operating member 43 accommodate the respective detecting probes 55 through the operating member 43 into the instrument bore 46 thereof. The detecting probes 55 terminate in the instrument bore 46 in distal, instrument engaging ends 56 for engaging the distal end 14 of the instrument 10 in the instrument bore 46.

Second guide means comprising guide bores 68 extending through the respective carrier elements 51 slideably engage the corresponding carrier probes 55 and guide the carrier probes 55 radially inwardly and outwardly of the instrument bore 46 of the operating member 43, as will be described in detail below.

The detecting probes 55 are urgeable distally along the guide slots 60 from a first state and an extended state illustrated in FIG. 1 with the detecting probes 55 adjacent the proximal ends 62 of the guide slots 60, and with the distal, instrument engaging ends 56 of the detecting probes 55 extending into the instrument bore 46 of the operating member 43, to a second state illustrated in FIG. 5 with the detecting probes 55 adjacent distal ends 63 of the guide probe slots 60 and still in the extended state. The detecting probes 55 are urged distally from the first state thereof to the second state thereof by the distal end 14 of the instrument 10 engaging the distal, instrument engaging ends 56 of the detecting probes 55, as the instrument 10 is being urged distally through the instrument bore 46 of the operating member 43. As the detecting probes 55 are being urged distally from the first state to the second state by the instrument 10, the carrier member 50 is urged from the proximal state to the distal state, and in turn the operating member 43 is urged from the disengaged state to the engagement state by the action of the detecting probes 55 on the carrier member 50.

When the detecting probes 55 are in the second state, the detecting probes 55 are slideable in the guide bores 68 of the carrier elements 51 from the extended state illustrated in FIG. 5 extending into the instrument bore 46 of the operating member 43, to a third state illustrated in FIGS. 4 and 6 with the distal, instrument engaging ends 56 of the detecting probes 55 withdrawn towards the probe accommodating openings 61 of the operating member 43 and clear of the instrument 10, in order to permit passage of the instrument 10 distally through the instrument bore 46 past the detecting probes 55. The distal, instrument engaging ends 56 of the detecting probes 55 define engagement surfaces 64, which are inclined distally inwardly in a direction towards the main central axis 35 for cooperating with the distal end 14 of the instrument 10, for urging the detecting probes 55 from the extended state to the third state when the detecting probes 55 are in the second state. Once the distal end 14 of the instrument 10 has passed the detecting probes 55 distally, the action of the instrument 10 on the detecting probes 55, as will be described below, retains the detecting probes 55 in the third state for retaining the detecting probes in the second state, and in turn for retaining the operating member 43 in the engagement state, for so long as the instrument 10 remains in the instrument bore 46 in engagement with the detecting probes 55.

Each detecting probe 55 comprises a probe shaft 67 of rectangular transverse cross-section. The probe shaft 67 is slideable in the guide bore 68 of the corresponding carrier element 51. The guide bore 68 of each carrier element 51 is also of rectangular transverse cross-section corresponding to that of the corresponding probe shaft 67 for keying the probe shaft 67 in the guide bore 68, and also for slideably guiding the probe shaft 67, and in turn the corresponding detecting probe 55 radially between the extended state and the third state. The probe shafts 67 terminate adjacent the cylindrical wall 53 of the carrier member 50 in end elements 70. Slots 71 in the cylindrical wall 53 of the carrier member 50 accommodate the end elements 70 when the detecting probes 55 are in the third state.

Each probe shaft 67 terminates towards the distal end thereof in an abutment member 72, from which the distal, instrument engagement end 56 of the corresponding detecting probe 55 extends. The abutment members 72 of the respective detecting probes 55 define abutment faces 79, which slideably engage abutment surfaces 83 recessed into the tubular housing 27 on respective opposite sides of the corresponding guide slots 60, for retaining the detecting probes 55 in the extended state as the detecting probes 55 are being urged from the first state to the second state by the distal end 14 of the instrument 10. The guide slots 60 terminate adjacent the distal ends 63 thereof in respective abutment member accommodating recesses 66 for accommodating the corresponding abutment members 72 therein in order to permit the detecting probes 55 to slide radially from the extended state to the third state when the detecting probes 55 have reached the second state thereof.

Additionally, the abutment member accommodating recesses 66 cooperate with the abutment members 72 act as retaining means for retaining the detecting probes 55 in the second state, for so long as the detecting probes 55 are in the third state, for in turn preventing the detecting probes 55 returning from the second state to the first state. The abutment member 72 of each detecting probe 55 forms with the corresponding abutment member accommodating recess 66 a pair of interengageable complementary formations to form the retaining means. The detecting probes 55 are retained in the third state thereof by the action of the instrument 10 in the instrument bore 46 of the operating member 43 on the distal, instrument engaging ends 56 of the detecting probes 55. A first camming means comprising a camming surface 77 provided on the abutment member 72 of each detecting probe 55, and inclining distally outwardly relative to the main central axis 35, cooperates with the corresponding similarly inclined camming surfaces 78, defined in the corresponding abutment member accommodating recesses 66, for a purpose to be described below.

An urging means, for urging the operating member 43 from the engagement state to the disengaged state comprises a compression spring 74 extending around the carrier member 50, and acting between the distal wall 24 of the housing 20 and an annular engagement flange 75 extending radially outwardly from and circumferentially around the cylindrical wall 53 of the carrier member 50 adjacent a proximal end 76 thereof. The compression spring 74 acts on the carrier member 50 for urging the carrier member 50 from the distal state to the proximal state, and in turn acts on the detecting probes 55 for urging the detecting probes 55 from the second state to the first state, when the detecting probes 55 are in the extended state.

The camming surfaces 77 of the abutment members 72 of the detecting probes 55, and the camming surfaces 78 in the abutment member accommodating recesses 66 cooperate with the compression spring 74, so that when the distal end 18 of the instrument 10, moving proximally in the instrument bore 46, has just passed the detecting probes 55 in the second states, the urging action of the compression spring 74 on the carrier member 50, results in the detecting probes 55 being urged from the third state to the extended state, and then the detecting probes 55 follow the distal end 14 of the instrument 10, as the detecting probes 55 are urged from the second state to the first state. This in turn results in the carrier member being urged under the action of the compression spring 74 from the distal state to the proximal state. As the carrier member 50 is being urged from the distal state to the proximal state, the operating member 43 is urged with the carrier member 50 from the engagement state to the disengaged state.

Therefore, as the instrument 10 is being withdrawn proximally through the instrument bore 46 of the operating member 43, and the distal end 14 of the instrument 10 passes the detecting probes 55, the detecting probes 55 are urged from the third state to the extended state by the action of the compression spring 74. Under the action of the compression spring 74 the detecting probes 55 follow the distal end 14 of the instrument 10 as the instrument 10 is being withdrawn proximally through the instrument bore 46, and the operating member 43 is urged from the engagement state to the disengaged state.

Returning now to the proximal seal 40, the proximal seal 40 comprises a disc shaped sealing element 84 having a central opening 85 extending therethrough and defining an inner peripheral sealing edge 86. The central opening 85 is sized and configured for sealably engaging the outer circumferential surface of an instrument, such as the instrument 10 in the instrument passageway 29. In this embodiment of the invention the central opening 85 is sized to seal against a laparoscope in the instrument passageway 29. The sealing element 84 comprises a flexible resilient material, typically, a flexible resilient polymer material with rubber-like elastic characteristics and is deformable into the non-sealing state in response to the proximal end 44 of the operating member 43 extending through the central opening 85 when the operating member 43 is in the disengaged state. The inherent resilience of the sealing element 84 is such as to return the sealing element 84 into the sealing state as the proximal end 44 of the operating member 43 disengages the sealing element 84 as the operating member 43 is being urged from the disengaged state to the engagement state.

The sealing element 84 is located in an annular seal accommodating recess 88 which extends into the tubular housing 27 from the instrument passageway 29 and circumferentially around the instrument passageway 29 adjacent the proximal end 30 thereof. The seal accommodating recess 88 is configured for accommodating the sealing element 84 therein in the non-sealing state, and shielded from the instrument 10 by the proximal end 44 of the operating member 43 when the operating member 43 is in the disengaged state. A circumferentially extending retaining recess 89 extends into the tubular housing 27 from the seal accommodating recess 88 and around the seal accommodating recess 88 for retaining the sealing element 84 captive in the seal accommodating recess 88.

A pair of seal engaging projecting members 87 extend longitudinally from the proximal end 44 of the operating member 43 equi-spaced apart circumferentially around the operating member 43 to form a lead-in to progressively engage the sealing element 84, as the operating member 43 is being urged from the engagement state to the disengaged state.

A plurality of collecting ports 90 are located equi-spaced apart circumferentially around the instrument passageway 29 adjacent the proximal end 30 thereof for collecting insufflating and other gases which may pass proximally through the instrument passageway 29, and in turn past the proximal seal 40. The collecting ports 90 extends inwardly from the instrument passageway 29 into the tubular housing 27 and communicate with an annular gallery 92 extending circumferentially around the tubular housing 27 and within the tubular housing 27 adjacent the proximal end 30 thereof. A connecting port 93 extending radially outwardly from and communicating with the annular gallery 92 is configured for coupling to a vacuum system (not shown) for applying a vacuum to the collecting ports 90 through the annular gallery 92. The vacuum system (not shown) draws any insufflating and other gases from the annular gallery 92 through a suitable filter (not shown) for filtering out particulate matter, including but not limited to pathogens, for example, viruses, infections and other particulate matter for cleaning the insufflating and other gases prior to being safely dispersed into the environment.

A pair of securing member accommodating slots 94 are located in the distal wall 24 of the housing 20 for accommodating the securing members 11 of the trocar cannula 3 into the hollow interior region 25 of the housing 20. An abutment shoulder 95 extending circumferentially around and radially inwardly into the hollow interior region 25 from the outer peripheral wall 22 spaced apart above the securing bracket accommodating slots 94, releasably engage engagement lugs 96 extending outwardly from the securing members 11 with a snap-fit action for releasably retaining and securing the housing 20 and in turn the attachment 1 to the proximal end 5 of the trocar cannula 3.

In use, with the detecting probes 55 urged into the first state and also in the extended state by the urging action of the compression spring 74 urging the carrier member 50 into the proximal state, and with the operating member 43 urged into the disengaged state retaining the proximal seal 40 in the non-sealing state in the seal accommodating recess 88, the attachment 1 is secured to the trocar cannula 3 by urging the securing members 11 of the trocar cannula 3 through the securing member engagement slots 94 in the distal wall 24 of the housing 20 until the lugs 96 of the securing members 11 engage the abutment elements 95 with a snap-fit action for releasably securing the attachment 1 to the trocar cannula 3.

The connecting port 93 is connected to the vacuum system (not shown) for drawing a vacuum in the collecting ports 90.

With the attachment 1 engaged with the proximal end 5 of the trocar cannula 3, and with the detecting probes 55 in the first state and the operating member 43 in the disengaged state, the duckbill valve 12 of the trocar cannula 3 is in the closed state, and the proximal seal 40 is retained in the non-sealing state by the operating member 43 and shielded from the instrument bore 46 of the operating member 43.

An instrument, for example, the instrument 10, such as a laparoscope is then entered into the instrument passageway 29 adjacent the proximal end 30 thereof, and is urged distally into the instrument passageway 29, and in turn into the instrument bore 46 of the operating member 43. Since the proximal seal 40 is retained in the non-sealing state in the seal accommodating recess 88 by the proximal end 44 of the operating member 43, which is still in the disengaged state, the distal end 14 of the instrument 10 passes the proximal seal 40 without being engaged by the proximal seal 40. As the distal end 14 of the instrument 10 commences to engage the distal, instrument engaging ends 56 of the detecting probes 55, and the instrument 10 is further urged distally through the instrument bore 46, the detecting probes 55 are urged distally through the guide slots 60 from the first state to the second state. As the detecting probes 55 are being urged from the first state to the second state, the operating member 43 is urged from the disengaged state to the engagement state by the action of the detecting probes 55 on the carrier member 50, thereby compressing the compression spring 74. As the proximal end 44 of the operating member 43 disengages the proximal seal 40, the proximal seal 40 transitions under its own inherent resilience from the non-sealing state to the sealing state, thereby sealably engaging the instrument 10, and in turn sealing the instrument passageway 29. The transition of the proximal seal 40 from the non-sealing state to the sealing state is completed before the operating member 43 reaches the engagement state.

As the operating member 43 is being urged from the disengaged state to the engagement state, the distal end 45 of the operating member 43 commences to engage the duckbill valve 12 in the trocar cannula 3 to commence opening thereof. By the time the operating member 43 is in the engagement state, the operating member 43 is extending through the duckbill valve 12, with the duckbill valve 12 in the open state, and shielding the instrument 10 from the duckbill valve 12. Thus, contact of the instrument 10 with the duckbill valve 12 is avoided as the instrument 10 is passing the duckbill valve 12, and there is no danger of contamination of the instrument 10 by any matter which may have been previously deposited on the duckbill valve 12 of the trocar cannula 3.

Once the detecting probes 55 have been urged by the distal end 14 of the instrument 10 into the second state, further urging of the instrument 10 distally through the instrument bore 46 of the operating member 43 results in the cooperating action between the distal end 14 of the instrument 10 and the inclined engagement surfaces 64 of the distal, instrument engaging ends 56 of the detecting probes 55 urging the detecting probes 55 radially outwardly of the instrument bore 46 of the operating member 43 from the extended state into the third state. As the detecting probes 55 are urged into the third state, the abutment members 72 thereof engage the abutment member accommodating recesses 66, which in turn retain the detecting probes 55 in the second state. For so long as the instrument 10 bearing on the distal, instrument engaging ends 56 of the detecting probes 55, remains in the instrument bore 46, to retain the detecting probes 55 in the third state, the retaining action of the abutment member accommodating recesses 66 on the abutment members 72 retain the detecting probes 55 in the second state.

Withdrawal of the instrument 10 through the instrument bore 8 of the trocar cannula 3 and in turn through the instrument bore 46 of the operating member 43 and the instrument passageway 29 of the attachment 1 is essentially the reverse of the insertion of the instrument 10 into and through the attachment 1 and the trocar cannula 3. The operating member 43 is retained in the engagement state by the detecting probes 55 for so long as the detecting probes 55 are in the second state, and are urged into the third state by the presence of the instrument 10 in the instrument bore 46 of the operating member 43. On the distal end 14 of the instrument 10 passing proximally past the distal, instrument engaging ends 56 of the detecting probes 55, the detecting probes 55 are urged radially inwardly through the probe accommodating openings 61 into the instrument bore 46 of the operating member 43 from the third state to the extended state by the urging action of the compression springs 74 urging the carrier member 50 proximally from the distal state to the proximal state.

In the extended state of the detecting probes 55, the abutment members 72 of the detecting probes 55 disengage the abutment member accommodating recesses 66 at the distal ends 63 of the guide slots 60, and thus, the detecting probes 55 under the action of the compression spring 74 on the carrier member 50 are urged proximally to follow the distal end 14 of the instrument from the second state to the first state. As the detecting probes 55 are being urged from the second state to the first state, the operating member 43 is urged from the engagement state to the disengaged state. This in turn results in the distal end 45 of the operating member 43 disengaging the duckbill valve 12 in the trocar cannula 3 which transitions from the open state to the closed state, and also results in the proximal end 44 of the operating member 43 urging the proximal seal 40 from the sealing state to the non-sealing state.

Accordingly, the duckbill valve 12 of the trocar cannula 3 is retained in the open state by the operating member 43 and is shielded by the operating member 43 from the instrument 10 until the distal end 14 of the instrument 10 has been withdrawn proximally past the duckbill valve 12. Additionally, the proximal valve 40 is urged into the non-sealing state by the operating member 43 and is shielded by the operating member 43 priorto the distal end 14 of the instrument 10 passing the proximal seal 40. Therefore, there is no danger of the instrument 10 depositing any biological or surgical matter on either the duckbill valve 12 or the proximal seal 40 as the instrument 10 is being withdrawn through the attachment 1.

Additionally, as the operating member 43 is being urged from the engagement state to the disengaged state on withdrawal of the instrument 10, the duckbill valve 12 is operated from the open state to the closed state, while the proximal seal 40 is being urged from the sealing state to the non-sealing state, thereby leaking of gases proximally through the instrument passageway 29 during withdrawal of the instrument 10 through the instrument passageway 29 is minimised, if not eliminated. Similarly, during insertion of the instrument 10 through the instrument passageway 29 leaking of gases proximally through the instrument passageway 29 is likewise minimised, if not eliminated.

However, any such insufflating and other gases which may pass proximally through the instrument passageway 29, and in turn pass through the proximal seal 40 are drawn into the collecting ports 90 by the vacuum applied thereto, thereby, avoiding any danger of insufflating and other gases passing into the environment from the proximal end 30 of the instrument passageway 29.

Referring now to FIGS. 18 and 20 there is illustrated an attachment according to another embodiment of the invention indicated generally by the reference numeral 100 also for attaching to the proximal end 5 of a trocar cannula 3 for operating an access valve in the trocar cannula from a closed state to an open state, and also for minimising the escape of insufflating and other gases passing proximally through the trocar cannula from a cavity of a subject being insufflated. The attachment 100 is substantially similar to the attachment 1, and similar components are identified by the same reference numerals. The only difference between the attachment 100 and the attachment 1 relates to the proximal seal, which in this embodiment of the invention is indicated by the reference numeral 103. The proximal seal 103 comprises an annular seal and is mounted on the proximal end 44 of the operating member 43 and extends circumferentially around the proximal end 44 thereof. The proximal seal 103 comprises a resilient elastic type material, and is of substantially semi-circular transverse cross section.

The proximal seal 103 is configured to transition from a non-sealing state illustrated in FIG. 18 to a sealing state illustrated in FIGS. 19 and 20 in response to the operating member 43 being urged from the disengaged state to the engagement state. In the non-sealing state an outer circumferential surface 105 thereof is of semi-circular cross-section, and an inner circumferential surface 106 is of a cylindrical shape and of diameter substantially similar to the diameter of the instrument bore 46 of the operating member 43, so that in the non-sealing state the proximal seal 103 is clear of the instrument bore 46, and in turn clear of the instrument 10 in the instrument bore 46. In the sealing state the circumferential inner surface 106 of the proximal seal 103 is of semi-circular cross-section and extends into the instrument bore 46 of the operating member 43 for sealably engaging the instrument 10 extending through the instrument bore 46 of the operating member 43. In this configuration, the outer circumferential surface 105 of the proximal seal 103 is of substantially cylindrical shape and is of diameter substantially similar to the outer diameter of the operating member 43.

An annular seal accommodating recess 108 is formed into the tubular housing 27 from the instrument passageway 29 and extends circumferentially around the instrument passageway 29 adjacent the proximal end 30 of the instrument passageway 29 for accommodating the proximal seal 103 in the non-sealing state. The seal accommodating recess 108 adjacent the distal end thereof terminates in a second camming means formed by a distal frusto-conical camming surface 110 for engaging and urging the proximal seal 103 from the non-sealing state to the sealing state as the operating member 43 is urged from the disengaged state to the engagement state. The frusto-conical surface 110 converges distally, and terminates at its distal end 111 in the instrument passageway 29 in a cylindrical engagement surface 112. The cylindrical engagement surface 112 is co-operable with the proximal seal 103 for retaining the proximal seal 103 in the sealing state.

The proximal seal 103 is configured such that in its normal relaxed state, the proximal seal 103 is in the non-sealing state. The inherent resilience of the proximal seal 103 transitions the proximal seal 103 from the sealing state to the non-sealing state as the proximal seal 103 is being urged proximally from the engagement surface 112 past the camming surface 110 to the seal accommodating recess 108 by the operating member 43, as the operating member 43 is being urged from the engagement state to the disengaged state.

Otherwise, the attachment 100 is similarto the attachment 1 described with reference to FIGS. 1 to 17 , and its use is likewise similar. As the operating member 43 is being urged from the disengaged state to the engagement state, by the carrier member 50 being urged from the proximal state to the distal state, by the action of the detecting probes 55 being urged from the first state to the second state by a distal end of an instrument, such as the instrument 10, being urged distally through the instrument bore 46 of the operating member 43, the proximal seal 103 is urged distally in the seal accommodating recess 108 by the operating member 43. As the proximal seal 103, moving distally, engages the frusto-conical camming surface 110, the proximal seal 103 is transitioned from the non-sealing state to the sealing state, and is retained in the sealing state by the action of the engagement surface 112 on the proximal seal 103. On withdrawal of the instrument 10 through the attachment 1, as the operating member 43 is being urged proximally in the instrument passageway 29 from the engagement state to the disengaged state by action of the compression spring 74 on the carrier member 50, the proximal seal 103 is urged from the engagement surface 112 past the frusto-conical camming surface 110, and thereby transitions from the sealing state to the non-sealing state under its own inherent resilience.

While the attachments described with reference to FIGS. 1 to 20 for the trocar cannula have been described as comprising a housing of a particular shape and construction, the attachments may be provided with housings of any other suitable shape or construction. Indeed, in some embodiments of the invention the housings may be provided without the peripheral wall and the proximal wall, and in which case, may be located directly in a proximal trocar housing of a trocar, to operate an access valve in a trocar cannula of the trocar.

It will also be appreciated that any other suitable urging means for urging the detecting probes proximally from the second state to the first state may be provided besides a compression spring, and needless to say, any other suitable means for urging the detecting probes from the third state to the extended state besides the compression spring cooperating with the first camming means may also be provided. Indeed, in some embodiments of the invention it is envisaged that a separate urging means may be provided for urging the detecting probes from the third state to the extended state which would be separate and independent of the urging means for urging the carrier member from the distal state to the proximal state, and in turn for urging the detecting probes from the second state to the first state.

Needless to say, while the attachments have been described as comprising two detecting probes equispaced apart around the instrument passageway, any other suitable number and arrangement of detecting probes may be provided, and in some embodiments of the invention, a single detecting probe only may be provided.

It will also be appreciated that while the detecting probes have been carried on a carrier member extending around the tubular housing 27, any other suitable carrier means for carrying the detecting means may be provided. Indeed, in an embodiment of the invention where only a single detecting means is provided, it will be readily apparent to those skilled in the art that other suitable mounting arrangements may be provided for mounting the detecting means, so that the detecting means is urgeable between the first state and the second state, for example, the detecting means may be pivotally mounted and would be pivotal between the first and second states. It is also envisaged that the detecting probe or probes may be mounted directly onto the operating member and would be urgeable relative to the operating member from the extended state to the third state.

Additionally, while specific proximal sealing means have been described, any other suitable proximal sealing means may be provided.

It will be appreciated that in some embodiments of the invention the proximal seal may be omitted, and it is also envisaged in some embodiments of the invention the collecting ports may be omitted.

In other embodiments of the invention, it is envisaged that instead of providing the operating means as an active operating means operable between a disengaged state and an engagement state for operating the access valve of a trocar cannula from the closed state to the open state, the operating means may be provided as a passive operating means, which would, for example, be a static operating member rigidly or releasably attached to the housing. Such a static operating member typically would project distally from the housing, so that when the attachment is engaged on the proximal end of the trocar or the trocar cannula, the static operating member would extend into the trocar cannula for engaging and operating the access valve therein from the closed state to the open state, and for retaining the access valve in the open state until the attachment had been removed from the trocar or the trocar cannula, thereby disengaging the operating member from the access valve of the trocar or the trocar cannula. In such an embodiment, it is envisaged that the proximal seal may be omitted. However, it is envisaged that the collecting ports would be provided for collecting any insufflating and other gases passing proximally through the instrument passageway of the attachment under a vacuum drawn on the collecting ports.

While the attachments described with reference to FIGS. 1 to 20 have been described for operating a particular type of access valve, namely, a duckbill valve in a trocar cannula, it will be appreciated that the attachments according to the invention may be used, with or without adaptation, for operating many other type of access valves in a trocar or a trocar cannula from a closed state to an open state, for example, the attachments according to the invention may be used for attachment to a trocar or a trocar cannula for operating any other type of duckbill valve besides that described, and the attachments according to the invention may also be used for operating other types of access valves of a trocar or a trocar cannula, for example, dome access valves, cross-slit access valves, or any other such access valves in a trocar or a trocar cannula from a closed state to an open state.

While the proximal seal 103 of the attachment described with reference to FIGS. 18 to 20 has been described as being of a specific shape, and in particular, is of shape which transitions from having a semi-circular inner peripheral edge to a semi-circular outer peripheral edge as the proximal seal 103 is transitioning from the sealing state to the non-sealing state, it will be appreciated that the cross-section of the proximal seal 103 may be of any other suitable or desired transverse cross-section.

While the instrument bore 46 in the operating member 43 has been described for accommodating a laparoscope therethrough, it will be readily apparent to those skilled in the art that the instrument bore 46 of the attachments of FIGS. 1 to 17 and FIGS. 18 to 20 , may be configured to accommodate any other instrument, for example, an endoscope or any other such surgical or medical instrument. In general, it is envisaged that the proximal seal will be sized to suit the instrument to which the instrument bore of the attachment is configured to accommodate. Needless to say, it will be appreciated that the attachments described with reference to FIGS. 1 to 17 and FIGS. 18 to 20 may be configured to accommodate a number of different instruments, and in which case, the proximal seal would be selected to be adjustable or of suitable shape to sealably engage a range of such instruments.

While the attachments according to the invention have been described for securing to the proximal end of a trocar cannula, it is envisaged that the attachments according to the invention may also be secured to a trocar, whereby the attachments would be secured to the proximal end of the proximal trocar housing, and in which case, a suitable securing means would be provided for securing the attachments to the proximal trocar housing of the trocar. The operating means if desired may then be configured to operate an access valve in the proximal trocar housing from the closed state to the open state. 

1-120. (canceled)
 121. An attachment for a trocar or a trocar cannula, the trocar or the trocar cannula being of the type comprising an access valve adjacent a proximal end thereof, the attachment comprising a housing defining an instrument passageway extending through the housing from a proximal end to a distal end for accommodating an instrument therethrough, the instrument passageway defining a longitudinally extending main central axis, the housing being engageable with the trocar or the trocar cannula with the instrument passageway aligned with an instrument bore of the trocar or the trocar cannula, and an operating means for operating the access valve in the trocar or the trocar cannula from a closed state to an open state.
 122. An attachment as claimed in claim 121 in which the attachment is engageable with a proximal end of the trocar or the trocar cannula, and preferably, the operating means is configured to engage the access valve of the trocar or the trocar cannula, and advantageously, the operating means is configured to extend into the access valve of the trocar or the trocar cannula, and preferably, the operating means is configured to extend through the access valve of the trocar or the trocar cannula, and advantageously, the operating means is aligned with the instrument passageway, and preferably, the operating means comprises at least one elongated operating member, and advantageously, the operating means comprises a pair of spaced apart operating members, and preferably, the operating members are spaced apart around the main central axis, and advantageously, the operating means defines an instrument bore for accommodating an instrument therethrough, and preferably, the instrument bore of the operating means defines a central axis coinciding with the main central axis defined by the instrument passageway, and advantageously, the operating means comprises a passive operating means, and preferably, the operating means comprises a static operating means projecting from the housing, and advantageously, the operating means is configured to engage the access valve of the trocar or the trocar cannula as the attachment is being engaged with the trocar or the trocar cannula, and preferably, the operating means extends distally from the housing.
 123. An attachment as claimed in claim 121 in which the operating means comprises an active operating means moveably mounted from a disengaged state disengaged from the access valve of the trocar or the trocar cannula to an engagement state engageable with the access valve of the trocar or the trocar cannula for operating the access valve from the closed state to the open state, and preferably, a detecting means is provided and is configured to detect an instrument entering or passing distally through the instrument passageway, and advantageously, the operating means is urgeable from the disengaged state to the engagement state in response to the detecting means detecting insertion of the instrument entering or passing distally through the instrument passageway.
 124. An attachment as claimed in claim 123 in which the operating means is slideable from the disengaged state to the engagement state, and preferably, the operating means is slideably mounted in the housing, and advantageously, the operating means is located in the instrument passageway, and is slideable therein from the disengaged state to the engagement state.
 125. An attachment as claimed in claim 123 in which the detecting means is urgeable from a first state to a second state in response to the instrument entering or passing distally through the instrument passageway, and preferably, the detecting means is urgeable distally from the first state to the second state, and advantageously, the operating means is urgeable from the disengaged state to the engagement state in response to the detecting means being urged from the first state to the second state.
 126. An attachment as claimed in claim 123 in which the detecting means extends into the instrument passageway in an extended state in the first state thereof, and preferably, the detecting means terminates in a distal, instrument engaging end adapted to engage an instrument being entered into or passing distally through the instrument passageway when the detecting means is in the extended state, and advantageously, the distal, instrument engaging end of the detecting means is adapted to engage a distal end of an instrument being entered into or passing through the instrument passageway when the detecting means is in the extended state, and preferably, the detecting means is urgeable from the first state to the second state by an instrument passing distally through the instrument passageway.
 127. An attachment as claimed in claim 123 in which the detecting means in the second state thereof is urgeable from the extended state extending into the instrument passageway to a third state, and preferably, the detecting means is urgeable from the extended state to the third state to accommodate an instrument passing the detecting means when the detecting means is in the second state, and advantageously, the detecting means is urgeable radially relative to the main central axis from the extended state to the third state, and preferably, the detecting means is urgeable from the extended state to the third state in response to an instrument in the instrument passageway, and advantageously, the detecting means is adapted to be urgeable by an instrument in the instrument passageway from the extended state to the third state, and preferably, the detecting means in the third state is adapted to engage an instrument in the instrument passageway, and advantageously, the detecting means is adapted to be retained in the third state by an instrument in the instrument passageway engaging the detecting means, and preferably, the detecting means in the second state thereof is moveable from the third state to the extended state in response to a distal end of an instrument being withdrawn from the instrument passageway in a proximal direction past the detecting means, and advantageously, the detecting means in the second state thereof is moveable from the third state to the extended state in response to a distal end of an instrument being withdrawn through the instrument passageway in a proximal direction past the detecting means.
 128. An attachment as claimed in claim 123 in which the detecting means is urgeable longitudinally along the instrument passageway from the first state to the second state, and preferably, a first guide means is provided for guiding the detecting means from the first state to the second state, and advantageously, the detecting means extends into the instrument passageway through the first guide means, and preferably, the first guide means comprises a first guide slot extending into the housing from the instrument passageway and longitudinally along the instrument passageway, and advantageously, a second guide means is provided for guiding the detecting means from the extended state to the third state.
 129. An attachment as claimed in claim 123 in which the detecting means is mounted on a carrier, and preferably, the carrier is located externally of the instrument passageway, and advantageously, the second guide means is mounted on the carrier, and preferably, the detecting means is slideably mounted on the carrier, and is slidable from the extended state to the third state.
 130. An attachment as claimed in claim 129 in which the operating means is coupled to the carrier, and preferably, the operating means is rigidly coupled to the carrier, and advantageously, the detecting means extends through a probe accommodating opening extending through the operating means communicating with the instrument bore defined by the operating means, and preferably, the detecting means in the extended state thereof is adapted to extend into the instrument bore defined by the operating means, and advantageously, the detecting means in the extended state thereof is adapted to engage an instrument in the instrument bore defined by the operating means.
 131. An attachment as claimed in claim 123 in which an urging means is provided for urging the operating means from the engagement state to the disengaged state, and preferably, the urging means is responsive to the detecting means being in the extended state for urging the operating means from the engagement state to the disengaged state, and advantageously, the urging means is responsive to the distal end of an instrument passing the detecting means proximally for urging the operating means from the engagement state to the disengaged state, and preferably, the urging means is adapted to urge the detecting means from the second state to the first state, and advantageously, the urging means is responsive to the distal end of an instrument passing the detecting means proximally for urging the detecting means from the second state to the first state, and preferably, the urging means is adapted to urge the detecting means from the third state to the extended state, and advantageously, the urging means is responsive to the distal end of an instrument passing the detecting means proximally for urging the detecting means from the third state to the extended state, and preferably, the urging means is cooperable with a first camming means for urging the detecting means from the third state to the extended state.
 132. An attachment as claimed in claim 123 in which a retaining means is provided for releasably retaining the detecting means in the second state while the detecting means is in the third state, and preferably, the retaining means is located adjacent the distal end of the first guide means, and advantageously, the retaining means comprises a pair of interengageable complementary formations, one of the interengageable complementary formations being formed in or on the housing and the other one of the interengageable complementary formations being formed in or on the detecting means, and preferably, the one of the interengageable complementary formations formed in the housing is formed adjacent the instrument passageway, and advantageously, the retaining means comprises the first camming means, and preferably, the detecting means is located proximal of the distal end of the instrument passageway, and advantageously, the detecting means is located spaced apart proximally from the distal end of the instrument passageway.
 133. An attachment as claimed in claim 123 in which the detecting means comprises a detecting probe, and preferably, the detecting probe terminates in the distal, instrument engaging end, and advantageously, the detecting means comprises an elongated detecting member, and preferably, the detecting means is engageable with the operating means for urging the operating means from the disengaged state to the engagement state, as the detecting means is being urged from the first state to the second state, and advantageously, the detecting means is engageable with the operating means for urging the operating means from the engagement state to the disengaged state, as the detecting means is urged from the second state to the first state.
 134. An attachment as claimed in claim 123 in which a sealing means is located in the instrument passageway for sealably engaging an instrument in the instrument passageway for minimising the passage of gases passing proximally through the instrument passageway, and preferably, the sealing means is located adjacent a proximal end of the instrument passageway, and advantageously, the sealing means is spaced apart proximally from the detecting means, and preferably, the sealing means comprises a flexible sealing means, and advantageously, the sealing means comprises a deformable flexible sealing means, and preferably, the sealing means comprises a resilient sealing means, and advantageously, the sealing means comprises an annular seal, and preferably, the sealing means extends circumferentially around the instrument passageway, and advantageously, the sealing means is mounted in a seal accommodating recess formed in the housing, and preferably, the seal accommodating recess extends into the housing from the instrument passageway, and advantageously, the seal accommodating recess extends circumferentially around the instrument passageway.
 135. An attachment as claimed in claim 134 in which the sealing means is transitionable from a non-sealing state disengaged from an instrument in the instrument passageway to a sealing state sealably engaging an instrument in the instrument passageway, and preferably, the sealing means is adapted to transition in a general radial direction from the non-sealing state to the sealing state, and advantageously, the sealing means is adapted to transition from the non-sealing state to the sealing state under its own inherent resilience, and preferably, the sealing means is adapted to transition from the sealing state to the non-sealing state under its own inherent resilience, and advantageously, the sealing means is transitionable from the non-sealing state to the sealing state in response to the detecting means detecting insertion of an instrument into the instrument passageway or an instrument being urged distally in the instrument passageway, and preferably, the sealing means is operable from the non-sealing state to the sealing state in response to the detecting means being urged from the first state to the second state, and advantageously, the sealing means is operable from the non-sealing state to the sealing state in response to movement of the operating means from the disengaged state to the engagement state, and preferably, the operating means is adapted in the disengaged state thereof to retain the sealing means in the non-sealing state, and advantageously, the operating means is adapted in the disengaged state thereof to engage the sealing means in the non-sealing state, and preferably, the operating means is adapted in the disengaged state thereof to shield an instrument in the instrument passageway from the sealing means, and advantageously, the sealing means is adapted to transition from the non-sealing state to the sealing state in response to disengagement thereof by the operating means, and preferably, the operating means is adapted to disengage the sealing means as the operating means is being urged from the disengaged state to the engagement state.
 136. An attachment as claimed in claim 135 in which the sealing means is mounted on the operating means and is moveable with the operating means, and preferably, the sealing means is urgeable from the non-sealing state to the sealing state in response to movement of the operating means from the disengaged state to the engagement state, and advantageously, a second camming means is provided adjacent the seal accommodating recess cooperable with the sealing means for urging the sealing means from the non-sealing state to the sealing state in response to movement of the operating means from the disengaged state to the engagement state, and preferably, the second camming means is located distally in the seal accommodating recess, and advantageously, the second camming means comprises a camming surface extending around the seal accommodating recess, and preferably, the camming surface is of frusto-conical shape, and advantageously, the camming surface converges distally.
 137. An attachment as claimed in claim 121 in which at least one collecting port is located in the instrument passageway for applying a vacuum adjacent the instrument passageway for drawing gases passing proximally through the instrument passageway therefrom, and preferably, the at least one collecting port is located adjacent the proximal end of the instrument passageway, and advantageously, the at least one collecting port is located proximal of the sealing means, and preferably, the at least one collecting port is located spaced apart proximally from the sealing means, and advantageously, a connecting port is provided for connecting the at least one collecting port to a vacuum system, and preferably, a plurality of the collecting ports are provided spaced apart circumferentially around the instrument passageway, and advantageously, a gallery is located in the housing with which the at least one collecting port communicates, and preferably, the connecting port extends from the gallery and advantageously, the housing comprises an elongated substantially tubular housing defining the instrument passageway.
 138. An attachment as claimed in claim 121 in which the operating means comprises a tubular operating member defining the instrument bore extending therethrough.
 139. A trocar comprising a trocar cannula and an attachment as claimed in claim 121 mounted on one of the trocar and the trocar Cannula.
 140. A trocar as claimed in claim 139 in which the attachment is mounted adjacent the proximal end of the one of the trocar and the trocar cannula, and preferably, the one of the trocar and the trocar cannula on which the attachment is mounted comprises an access valve located adjacent the proximal end thereof, the access valve being engageable by the operating means of the attachment for operating the access valve from a closed state to an open state, and advantageously, the access valve is operable from the closed state to the open state in response to engagement thereof by the operating means of the attachment, and preferably, the access valve is engageable by the operating means of the attachment when the operating means is in the engagement state, and advantageously, the access valve comprises a flexible membrane urgeable into the closed state under inherent resilience of the access valve, and preferably, the access valve is operable from the closed state to an open state by deforming the membrane thereof, and advantageously, the attachment is secured to the one of the trocar and the trocar cannula by engaging the housing of the attachment with the one of the trocar and the trocar cannula, and preferably, the attachment is releasably secured to the one of the trocar and the trocar cannula. 